1. Technical Field
The present invention relates to an organic EL device and to an electronic apparatus.
2. Related Art
An organic electroluminescent (EL) device is expected as a next-generation display device.
FIG. 9 is an explanatory diagram of an organic EL device according to a related art. FIG. 9A is a plan view, and FIG. 9B is a side sectional view taken along line IXB-IXB of FIG. 9A. As shown in FIG. 9A, a typical organic EL device includes a plurality of organic EL elements 3 which are arranged in a matrix. In more detail, as shown in FIG. 9B, a driving circuit 5 is provided on a glass element substrate 2, and the organic EL element 3 is provided on the driving circuit 5. The organic EL element 3 includes a pixel electrode 23 as an anode, an organic functional layer (a hole injection layer, a light-emitting layer 60, or an electronic transport layer), and a cathode 50, which are sequentially laminated. Current is supplied to the organic functional layer by using the pixel electrode 23 and the cathode 50 such that the light-emitting layer 60 can emit light.
A plurality of power lines 8 are provided on the driving circuit 5. The power lines 8 supply current from the periphery of the element substrate 2 to the pixel electrode 23. As shown in FIG. 9A, since a plurality of organic EL elements 3 are arranged in a matrix, a significant voltage drop due to the wiring line resistance of the power lines 8 occurs in the organic EL elements 3 located in a central portion of the substrate. The power lines 8 are arranged in a lattice shape to prevent the voltage drop due to the line resistance. In addition, it is possible to supply current to each organic EL element 3 using each of the power lines 8.
As shown in FIG. 9B, the power lines 8 are arranged around the organic EL element 3. The cathode 50 of the organic EL element 3 is provided on the entire surface of the substrate 2. The organic EL element is a current-controlled element. Since a large current flows in the cathode 50 so as to obtain sufficient luminance, a short circuit may occur in a portion between the power lines 8 and the cathode 50, which is denoted by an arrow 55. If the short circuit occurs in the portion between the power lines 8 and the cathode 50, a large current flows in the portion, such that the driving circuit is burned and causes short circuits to consecutively occur in adjacent portions. As shown in FIG. 9A, since the power lines 8 are formed in a lattice shape, a short circuit occurs in the entire substrate.
In the organic EL device according to a related art, the cathode has a low resistance so as to reduce a voltage drop due to the surface resistance of the cathode (refer to JP-A-2001-230086). In this configuration, since the current flowing in the cathode increases, a short circuit in the power lines is likely to occur.